Image Format Differences: JPEG vs PNG vs WebP

What each format actually is

JPEG, PNG, and WebP are three different ways of storing image data, each with its own strengths. JPEG is the long-standing standard for photographs, using lossy compression to produce small files from complex, colorful images. PNG is a lossless format built for sharp graphics, text, and anything needing transparency. WebP is a newer format designed to handle both photos and graphics efficiently, often beating both older formats on file size.

None of them is universally best. The right format depends on what the image contains and where it will be used, which is why understanding their differences pays off every time you export a file.

Lossy vs lossless, one more time

JPEG and WebP (in its lossy mode) discard image data to shrink files. This is fine for photos because the discarded detail is mostly invisible at normal viewing. PNG and WebP (in lossless mode) keep every pixel exactly, which preserves razor-sharp edges and text but produces larger files for photographic content.

The practical takeaway: choose lossy for photos where small size matters, and lossless for graphics where precision matters. Choosing wrong in either direction costs you either visible quality or unnecessary file weight.

Transparency: who supports it and who does not

PNG supports full transparency, which is why it remains the default for logos, icons, and overlays that must blend into any background. WebP also supports transparency, giving you the same capability at a smaller file size. JPEG does not support transparency at all, so any transparent areas become a solid color, usually white or black.

If your image needs a transparent background, JPEG is immediately off the table. Between PNG and WebP, WebP generally gives you smaller files, while PNG gives you the widest possible compatibility with older software.

File size comparison in plain terms

For a typical photograph, a PNG can easily be several times larger than the same image saved as JPEG or WebP, because lossless storage keeps data that lossy compression would quietly discard. Between JPEG and WebP at similar visual quality, WebP commonly produces noticeably smaller files, which is why it is popular for websites where every kilobyte affects loading speed.

For simple graphics with flat colors, PNG files stay small because there is little detail to store, and they remain perfectly sharp. Converting such graphics to JPEG often makes them both larger and blurrier, the worst of both worlds. Match the format to the content and the file size largely takes care of itself.

When to convert from one format to another

Convert PNG photos to JPEG or WebP when file size matters, such as images for the web. Convert JPEG graphics with text to PNG or WebP when sharpness matters, such as screenshots and diagrams. Convert to WebP when you want the smallest file and your audience uses modern browsers and apps.

Avoid converting back and forth between lossy formats: each conversion discards more data, so a JPEG converted to WebP and back to JPEG will look worse than the original. Always convert from the highest-quality source you have, and keep that source archived.

A note on browser and platform support

JPEG and PNG work everywhere without exception, which is why they remain safe defaults when compatibility is critical. WebP support is widespread across modern browsers, operating systems, and major platforms, but very old software may not open it. When in doubt about your audience's setup, JPEG for photos and PNG for graphics remain the zero-risk choices.

Support keeps improving over time, so the compatibility gap narrows every year. For most web publishing today, WebP is a practical default, with JPEG and PNG as reliable fallbacks.

Frequently asked questions